The present application relates to an imaging and display apparatus and an information input apparatus for obtaining information such as the position of an object touching or in close proximity to a display panel, and an object detection medium and method for obtaining such information.
In the art, techniques for detecting the position or the like of an object touching or in close proximity to a display surface of a display apparatus have been known. One typical well-known technique is a display apparatus having a touch panel.
There are various types of touch panels, and one well-known type of touch panel is the type that detects an electrostatic capacitance. This type of touch panel is designed such that a change in electric charge on a surface of the touch panel caused by touching the touch panel with an object such as a finger is detected to determine the position or the like of the object. A user can use such a touch panel to perform an intuitive operation.
For example, the assignee of the present application has proposed, in Japanese Unexamined Patent Application Publication No. 2004-127272, a display apparatus including a display unit (i.e., an imaging-and-display panel) having a display function for displaying an image and an imaging function (or detection function) for imaging (or detecting) an object.
The display apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2004-127272 allows detection of the position or the like of an object touching or in close proximity to the imaging-and-display panel, such as a finger, using display light reflected from the object on the basis of a captured image. With the use of the display apparatus, therefore, the position or the like of an object can be detected with a simple structure without using any additional component such as a touch panel on the imaging-and-display panel.
In the above-described structure in which display light reflected from an object is used, however, there is a problem involving the brightness of the display light. Specifically, the brightness of the display light affects the brightness of received light, and the brightness of the display light varies in accordance with image data. Therefore, for example, when black display is provided or when a backlight in a transflective liquid crystal display apparatus is continuously turned off (e.g., when the liquid crystal display apparatus is used outdoor), it is difficult to detect the position or the like of an object on the basis of a captured image.
Accordingly, in the related art, it is difficult to accurately detect an object touching or in close proximity to a display panel regardless of the current use condition such as the brightness of display light.